Inulin hydrolysis by kluyveromyces marxianus inulase produced on some agricultural wastes

High fructose syrup is produced by the action of inulase on inulin. Many yeast strains were used in this study for inulase production on some agricultural wastes. Results showed that Kluyveromyces marxianus was the most potential strain in inulase production among sixteen yeast strains. K. lactis and K. fragilis were found in the second order. 15 min. was chosen as the best reaction time. PH 5.5 and 6.0 was found as the optimum pH for K. lactis and K. fragilis and K. marxianus, respectively. Enzyme activity was maximal at 35C. K. marxianus inulase was maximized after 3 days of incubation and pH 7.5 at 30C. Biological wastes played an important role in K. marxianus inulase production. Dahlia tubers were the best carbon source for inulase synthesis. Also, chicory roots, orange peel and beet pulp gave high amount of inulase compared to other carbon sources. Ammonium nitrate induced inulase production by K. marxianus which was found as the best nitrogen source between all inorganic and organic ones. The degree of inulin hydrolysis reached 76.50% after 2 hr with 40 units of enzyme in 5% inulin solution. This revealed the importance of this enzyme in the production of fructose syrup from inulin; that industry is very important from healthy and economic viewpoints

Enzymatic saccharification of pretreated water hycinth and sugarcane baggasse with crude cellulase of a strain of Aspergillus terreus.

This work aimed to study the extent of enzymatic saccharification and cellulose conversion of alkali pretreated water hyacinth [WH] and sugar cane bagasse [SCB] by crude cellulase of a potent strain of A. terreus isolated from the residues of flax shives. Pretreated samples of WH and SCB contained 16 and 15% lignin, 58.9 and 51% cellulose and 10 and 22.5% hemicellulose, respectively. By cellulase action for 96 hours, alkali pretreated WH and SCB showed 82 and 74% saccharification and 66 and 54% cellulose conversion to glucose, respectively. An initial rapid adsorption of enzymes and protein to substrates occurred, followed by a decreased adsorption. The increase in units of filter paper [FP] activity/g WH or SCB from 20 to 100 units increased both saccharification and cellulose conversion of WH and SCB, respectively. An inhibition of the saccharification was observed in the presence of sugars or ethanol. The inhibition percentage was 100% when 7% glucose and 7% ethanol were present simultaneously